This invention pertains to sound reduction and absorption. More particularly, this invention pertains to an acoustic plug for reducing sound along window mullions and similar locations that have little or no sound insulation.
Sound generated inside a building can travel through the walls, and/or the floor and ceiling assemblies. This type sound comes from human activities in adjacent spaces or from mechanical noise within the building systems. Human generated sound activities can include voice, amplified sound, or animals, as well as foot traffic on the floor above a ceiling.
Although providing for a beautiful appearance, glass curtain wall facades are not designed to prevent noise transfer between interior spaces that line the outside walls of an office building. Interior walls and partitions have been developed to prevent noise transfer between rooms. Drop-in and other type ceilings provide for extra layers of sound insulation from above an office. However, a weak link in noise reduction occurs when walls and partitions are terminated at exposed window mullions.
FGI Guidelines for Healthcare Construction and International Building Code for Multi-Family Dwellings have minimum Sound Transmission Class (STC) requirements for demising walls. When tested as an assembly, a demising wall that terminates at an exposed mullion will not meet the minimum code requirements.
A standard mullion has an STC rating of 28. When the mullion is left exposed, sound will transfer between rooms and be a problem due to the poor noise deadening performance of the mullion.
Acoustical wall and ceiling panels are typically constructed of many different type materials, coverings, and/or finishes. Ideally the covering will have little impact on the acoustical capability of the sound absorption or blocking material.
Fabric covered panels are one way to maximize the acoustical absorption capabilities of the acoustical material. Mineral fiber board, or Micore, is one commonly used acoustical substrate. Fiberglass is another material that is commonly used as an acoustical substrate. Fabric or other finishing materials, such as wood or metal, are generally chosen to provide acoustical transparency, that is, they are chosen so as not to impede a sound wave.